THE INFLUENCE OF STARVATION ON WATERBORNE ZINC ACCUMULATION BY RAINBOW-TROUT, SALMO-GAIRDNERI, AT THE ONSET OF EPISODIC EXPOSURE IN NEUTRAL SOFT-WATER

Zinc accumulation by whole gill, skin, body mucus and blood plasma were measured during short term episodic exposure in acidic and neutral soft water using fed fish and also in neutral soft water using starved fish. Water pH did not influence zinc accumulation in 1 h using fed fish indicating that pH effects on zinc accumulation occur over a longer time period. The gill tissue and body mucus were primary sites of zinc accumulation in fed and starved fish, while plasma zinc increases were observed only in fed fish during a 2 h episode of neutral soft water. Starved fish gill tissue and body mucus accumulate zinc quicker than fed fish tissues. The increased zinc accumulation by starved fish may be explained in terms of an increased contribution by waterborne zinc to total body zinc levels, achieved partly by changes in mucus ion content and also by possible effects of starvation on tissue zinc distribution. © 1990.